Whose side of the story do you believe?

The ride is stiff. The steering is stiff. The clutch is stiff. The shifter is stiff.

Therein lies the charm.

This is the modern evocation of a classic muscle car. If it were not stiff, it would not require muscle.

Of course, the muscle designation refers to power, not effort. In this case, we’re talking about a hot 500 horsepower from a 4.6-liter V-8 engine with 32 valves, twin overhead camshafts and a supercharger.

It’s hooked to a six-speed manual gearbox that transfers the engine’s 480 foot-pounds of torque to the rear wheels, which are bolted to an old-fashioned solid rear axle. No automatic transmission is offered.

Back in the late 1960s and early 1970s, muscle cars were the rage. But they were spooky, with imprecise handling and questionable brakes. Ford pumped up its Mustang, the original pony car, by turning it over to performance impresario Carroll Shelby.

The result was the Shelby GT350 and the Shelby GT500, which were the hottest Mustangs of the era. With the introduction of the current-generation Mustang, Ford decided to return to those thrilling days of yesteryear by styling the new car close to what it looked like in 1967.

Naturally, that had to be followed by the 2007 Shelby GT500, which bears the distinction of being the most powerful Mustang ever made.

Mr. Shelby himself concedes that the early Mustangs that bore his name left a lot to be desired. “Great engines, couldn’t turn, couldn’t stop,” is how he described it.

But that was then, 40 years ago, when suspension, steering and brake design lagged behind engine development.

Mr. Shelby also concedes privately that he had little to do with the new GT 500. He describes himself as a businessman, not an engineer, and credits the new car’s tingling high performance to the engineers from Ford’s Special Vehicle Team. They get their due on the car, which carries the SVT initials on the door sill plates.

But despite the fact that Mr. Shelby is a midlevel octogenarian, his name remains magic among automobile aficionados who value brute power as expressed in good old Detroit iron.

The new car, however, is far from good old. Like the Mustang on which it is based, the GT500 benefits from sophisticated, computer-generated design and engineering that come together in a package that not only has awesome power but handling and braking that are enhanced by traction control, antilock brakes and electronic brake force distribution.

That translates into fuss-free hustle around tight turns, on a race track or twisting mountain road, as well as stops from freeway speeds that happen in less time than it takes to tell about it. On the performance front, the GT500 does not have a significant flaw, unlike its predecessors of four decades ago.

But it does have some of the old feel. Climb into the driver’s seat, and the high hood stretches out to the horizon. The GT500 has that old long hood, short deck design that almost makes it feel as if you’re driving from the back seat.

Like other Mustangs, it has a back seat that can accommodate a couple of adults, as long as they’re agile and of small stature. There’s no sliding passenger seat to ease entry into the back. The trunk is small but useful.

But the GT500 is not about practicality or accommodations. What it delivers is the thrill of raw power as you slam your way through the gears. Despite the stiffness, it is easy to drive smoothly, and the V-8 engine has the sort of rumble and rap that gets the juices flowing.

It is accompanied by a marvelous aural treat — a whine, the source of which can only be imagined as you punch the pedal in second and third gears. Is it the supercharger, or is it old-fashioned gear whine, of the sort you’d hear from a powerful 1930s era Packard or Cadillac in a noir movie?

Whatever, it’s exciting in a way you cannot experience in more refined machinery. It’s something like running a powerful V-twin Harley-Davidson motorcycle next to a slick Suzuki performance bike.

Though it looks terrific from the outside, way better than its oddly shaped predecessors of yore, and especially with the blue-and-white striped American racing colors, the GT500 has a plain-vanilla interior, serviceable but nothing to challenge a designer look. The front bucket seats are better than those in 99 percent of the Mustangs ever made, but still lack a bit of lateral support.

The base price of the Shelby GT500 is $42,975 and, with a $1,300 gas guzzler tax and a few options that included an upgraded Shaker audio system with a six-disc CD changer, the suggested price came to $44,880.

But that’s irrelevant.

The Shelby GT500 has created such a buzz among the faithful that some of them have paid $20,000 and more above the sticker price simply to be among the first to impress their friends at the local drive-in. Better to wait until things settle down.